From L.A. Streetsblog:

Land use rules implemented in the past to protect public health have today become health hazards.

As Emily Talen puts it in her book City Rules: How Regulations Affect Urban Form, “[z]oning contributed to health problems by spreading people out, increasing their reliance on automobiles and a sedentary lifestyle.” Rules that kept peoples’ homes in different districts than heavy industry were rapidly expanded to separate all commercial uses from residential zones. Starting in the 1930s, Los Angeles began required new buildings to provide on site parking for cars, subsidizing driving at the same time that separate use zoning was undercutting walking.

Full post here.